There are several types of non-volatile memory (non-volatile memory is referred to as NV memory hereinafter) such as SSD (see non-patent document 1) and EEPROM (see non-patent document 2). [[Non-patent Document 1: “What is SSD?” [online], IT Glossary e-Words, Searched on Jan. 23, 2013, Internet, [URL: http://e-words.jp/w/SSD.html]. Non-patent Document 2: “What is EEPROM?” [online], IT Glossary e-Words, Searched on Jan. 23, 2013, Internet, [URL: http://e-words.jp/w/EPROM.html].
As a result of several studies conducted in recent years for utilizing an NV memory as a main memory and utilizing a main memory as a storage, use of an NV memory as both a main memory and a storage without the area of the NV memory being divided into an area used as a main memory and an area used as a storage has been realized. When an NV memory is used as both a main memory and a storage, a main memory and a storage may be integrated, i.e. they can be treated as a memory without being distinguished from each other. If a main memory and a storage are integrated, efficiency of memory management in a system may be improved. However, when memory blocks managed by a file system are directly used as a part of a main memory, some problems of implementation and management may be caused. For example, according to known methods for using an NV memory as both a main memory and a storage, when a system is abnormally terminated, a file system may fail to manage files correctly.